Structural Characteristics and Development of Ampullary Organs in Acipenser naccarii

Abstract

Ampullary organs of Acipenser naccarii sturgeons were examined by optical and electronic microscopy (transmission electron microscopy and scanning electron microscopy) from hatching until 1 month later when the juvenile phase is completely established. It was observed that, when A. naccarii begins to feed actively, the ultrastructural characteristics of ampullary organs already correspond to those of adult animals. These organs may, therefore, be functional and, together with taste buds, facilitate food search after exhaustion of yolk sac food reserves. Mature ampullary organs of A. naccarii are formed by an ampulla that communicates with the exterior by means of a short channel. These ampullae correspond to the sensory portion of these receptors and are formed by two cell types: receptor cells and support cells. Receptor cells present a kinocilium on their free surface and establish ribbon synapses with axon nerve endings that arise from the underlying conjunctive tissue. Support cells enclose receptor cells, bear stereocilia and occasional cilia, and are of a secretory nature. The mucus associated with ampullary organs mainly comprises neutral mucopolysaccharides, whereas mucopolysaccharides are usually acid in other fish groups.

Neomycin damage and regeneration of hair cells in both mechanoreceptor and electroreceptor lateral line organs of the larval Siberian sturgeon (Acipenser baerii)

“…To explore whether sensory hair cells in ampullary organs are susceptible to aminoglycosides, we analyzed lateral line sensory hair cells by SEM in Siberian sturgeon larvae (stage 43–50) after exposure to neomycin. Previous studies have shown that new ampullary organs and new ampullary hair cells are continually added to the lateral line system in shovelnose sturgeon and Adriatic sturgeon during this phase (Gibbs and Northcutt, ; Camacho et al, ). In addition, the number of sensory hair cells in each neuromast and ampullary organ in untreated Siberian sturgeon larvae varies according to their position in the lateral line system (data not shown).…”

Morphological development in the first life phase of Adriatic sturgeon Acipenser naccarii under controlled conditions

“…From 2 dph, the first pair of branchials were formed, the barbel rudiments were visible and the mouth began to open, coinciding with the appearance of the ampullary organ anlages on the head epithelium as described by Camacho et al, 2007. The yolk sac, now longer, could be reflecting important changes such as those reported by Ostos-Garrido et al, (2009), who observed that the yolk sac begins to subdivide into the gastric and intestinal outlines.…”

“…Outlines of the taste buds began to appear in the barbels and the bud of the tongue is evident on the floor of the oral cavity. The first pores communicate with the exterior environment on the ventral surface of the head (Camacho et al, ). On the other hand, Ostos‐Garrido et al .…”

“…Although embryonic development of A. naccarii has recently been described (Cabrera et al, 2015), most of the available studies on this sturgeon species focus on morphological and physiological adjustments to changes in ambient salinity (Cataldi et al, 1995McKenzie et al, 1999McKenzie et al, , 2001aMcKenzie et al, , 2001bMartínez-Álvarez et al, 2002Martínez-Álvarez et al, , 2005Carmona et al, 2004), ontogenesis of various organs (Cataldi et al, 2002;Vázquez et al, 2002;Grandi & Chicca, 2004;Icardo et al, 2004;Gomez et al, 2009;Camacho et al, 2011), ampullary organs (Camacho et al, 2007), early ontogeny with special focus on the digestive tract and cutaneous receptors (Boglione et al, , 2006, some aspects related to feeding and nutrition (Agradi et al, 1993;Soriguer et al, 2002) and digestive (Furné et al, 2005(Furné et al, , 2008a and antioxidant (Trenzado et al, 2006;Furné et al, 2008b) capacities, however less is known about structural development at a macroscopic level.…”

Morphological structure and peripheral innervation of the lateral line system in the Siberian sturgeon (Acipenser baerii)

“…1). Teleost electroreceptors differ extensively from the ampullae in primitive fish with regard to their history, innervation, central projections, and physiology (Camacho et al 2007).…”